Shards naming scheme

[adlrocha]

In its current implementation, the ID of a shard is determined by computing the CID of the path of the shard using as suffix in the path the name selected for the shard (i.e. root/parent/<user_defined_name). The shard actor at the shard where the shard is being spawned checks before assigning the ID if another shard with the same name already exists.

According to the initial spec, instead of assigning the suffix of the path from the user-defined name, the shard actor will assign a new int suffix sequentially to every new shard spawned. This makes discovery and interaction with shards deterministic, and the traversal of the full hierarchy more efficient. (i.e. root/i/j

In the future we may chose to include a DNS-like service for the discovery of shards by name.

[adlrocha]

In the latest update of the spec, we don't use sequential number anymore but /root/parent/<ID of shard actor>, including the ID of the shard actor that implements the ShardingInterface for the shard. See #61, #62.